package cn.backpackerxl.easyJDBC.util;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Md5加密
 *
 * @author: backpackerxl
 * @create: 2021/10/29
 * @filename: MD5Passwd
 **/
public final class MD5Passwd {
    /**
     * MD5加密方法
     *
     * @param str 要加密的字符串
     * @param len 要加密的长度
     * @return 加密后的字符串
     */
    public static String code(String str, int len) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(str.getBytes());
            byte[] byteDigest = md.digest();
            int i;
            StringBuffer buf = new StringBuffer("");
            for (int offset = 0; offset < byteDigest.length; offset++) {
                i = byteDigest[offset];
                if (i < 0)
                    i += 256;
                if (i < 16)
                    buf.append("0");
                buf.append(Integer.toHexString(i));
            }
            //32位加密 or 16位的加密
            return len == 32 ? buf.toString() : buf.toString().substring(8, 24);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }

    }
}
